1. Field of the Invention
The present invention relates to a transport format determination apparatus (TF-determination apparatus) for determining a transport format (TF) in a wire-less transmission system, and a transport format determination method (TF-determination method) as well as a program to be executed for implementing the TF-determination method.
All of patents, patent applications, patent publications, scientific articles and the like, which will hereinafter be cited or identified in the present application, will, hereby, be incorporated by references in their entirety in order to describe more fully the state of the art, to which the present invention pertains.
2. Description of the Related Art
There has been known a wire-less transmission system regulated by a third generation partnership project (3GPP). FIG. 1 is a timing chart illustrative of a plurality of transport channels (TrCH#0), (TrCH#1) and (TrCH#2) with different transmission time intervals (TTIs) from each other, which are multiplexed in the wire-less transmission system. The transport channel (TrCH#0) has a transmission time interval (TTI) of 40 ms. The transport channel (TrCH#1) has a minimum transmission time interval (TTI) of 20 ms. The transport channel (TrCH#2) has a transmission time interval (TTI) of 80 ms. If TrCH#1 (1,0) with the minimum transmission time interval (TTI) is decoded to confirm that a result of a cyclic redundancy check (CRC) is “OK” or “not fault”, then it is presumed that a transport format combination indicator (TFCI) determination was correct, whereby other transport channels, for example, TrCH#0 (0,0) and TrCH#2 (2,0) can be defined.
If any transport channel (TrCH) with a defined transport format (TF) is present, for example “frame#2” and “frame#4”, then the TFCI are allowed to take limited values, for which reason a decoding performance of the TFCI can be improved by using its information.
The transport channel (TrCH) is a channel provided from a physical layer to a media access control (MAC) sub-layer. There are plural kinds of the transport channel (TrCH) for transmitting plural kinds of data different in property and transmission format over the physical layer. The transmission time interval (TTI) is defined to be a time interval between arrivals of transport block sets between the layers. The transport block set is also defined to a set of transport blocks as basic units of concurrent transmissions between a layer 1 and the media access control (MAC) sub-layer through the same transport channel (TrCH). The transmission time interval (TTI) is equal to a time interval of transferring the transport block sets by the layer 1 over a wire-less interface. The media access control (MAC) provides data to the layer 1 every transmission time interval (TTI). The layer 1 provides the cyclic redundancy check (CRC) every transport block.
The transport format (TF) is a format for supplying transport blocks every transmission time interval (TTI) over the transport channel (TrCH). The transport format combination indicator (TFCI) has a one-to-one correspondence to a transport format combination (TFC), whereby the layer 1 generates it from the transport format combination (TFC) and transmits it over a wire-less interface. On a receiving side layer 1, the transport format combination indicator (TFCI) is used for decoding the received data and isolating the transport blocks. The layer 1 allows multiplexing a plurality of the transport channels (TrCH), for which reason there exist a combination of the transport channels (TrCH) which are concurrently transferable over the layer 1. This combination is defined to be the transport format combination (TFC).
In accordance with the above-described conventional wire-less transmission system, if the transport channels (TrCH) with different transmission time intervals (TTI) from each other are multiplexed, then this allows that a result of decoding the transport format combination indicator (TFCI) be fault due to a transmission noise. In this case, it is possible that there are different transport formats (TF) to (2,0) data of the transport channel (TrCH#2) between the frame #0 and the frame #2, wherein the frame corresponds to the transport block. Namely, it is possible that the different transport formats (TF) are presented to the same data.
In the above circumstances, the development of a novel technique of reducing a possibility that different transport formats (TF) are presented to the same data is desirable.